Pressure hydrogenation of crude oils, tars or their residues



' constituents.

United States Patent 9 PRESSURE HYDROGENATION F CRUDE OILS, TARS 0RTHEIR RESIDUES Willi Oettinger, Ludwigshafen (Rhine), Germany, assiguorto Bathsche & Soda Fabrik Aktiengesellschaft, Ludwigshafen (Rhine),Germany N0 Drawing. Filed Mar. 18, 1958, Ser. No. 722,123

Claims priority, application Germany Mar. 21, 1957 7 Claims. (Cl.208-85) This invention relates to the removal of ash from crude oils,tars and their residues.

It is already known to lead the initial materials, in thedesulfurization of crude oils or their residues by refining pressurehydrogenation, over large-surfaced substances prior to the refiningtreatment proper. In this pretreatment, the inorganic constituentscontained in the crude oil or residue are retained in the preliminarystage so that the activity of the catalyst in the following refiningstage is not impaired by the deposition of ash In carrying out thismethod of working in practice, however, it has been found that inprolonged operational periods there often takes place a coking of thelarge-surfaced substance or that small amounts of ash constituents passinto the following refining stage and reduce the activity of thecatalyst therein.

I have now found that the said disadvantage can be avoided by preheatingthe initial materials, prior to the pressure hydrogenation proper, in apreliminary stage in the presence of large-surfaced substances in such away that the initial material is led into the preliminary stage at atemperature above 250 C., preferably above 300 C., but below 400 C., anda rise in temperature of the reaction material is effected in the samestage by at least about 30 C. and advantageously 50, 60, 75 C. or more.

The process according to this invention is suitable for all kinds ofpressure hydrogenation, for example for refining, destruction and/oraromatizing pressure hydrogenation, in which the high-boiling initialmaterial, such as crude oils, tars, especially bituminous or brown coaltars, shale oils or their residues boiling above 300 C., for exampledistillation, extraction or cracking residues, are Worked up. Theprocess according to this invention is further particularly suitable forrefining the initial materials mentioned above and for enlarging thequantity of lower boiling products as diesel oils, gas oils and fueloils.

The said initial materials are heated preferably in the presence ofhydrogen to at least 250 C., advantageously to at least 300 C., forexample to a temperature lying between 310 and 350 C., and then led intoa reaction chamber provided with large-surfaced substances. Thisreaction chamber may consist of one chamber or of a plurality ofsuccessive chambers. In this reaction chamber the temperature is allowedto rise, for example to 370 C., 400 C. or more. When using two vessels,the temperature distribution may be as follows: in the first vessel arising temperature within the range of from about 280 C. to about 360 C.is chosen and in the second vessel a rising temperature between about360 C. and the reaction temperature. By working in this way there isachieved a reliable removable of the ash without depositions of cokeoccurring. It is also possible to work, however, by allowing thetemperature to rise only in the second vessel, whereas a constant oreven slightly falling temperature is maintained in the first vessel.

It is advantageous to withdraw 0.1 to 2% by weight, with reference tothe initial material, of an ash-containing high-boiling oil from behindthe first reaction vessel or, when a plurality of successive vessels isused, preferably behind the second or last reaction vessel.

In general the heat evolved by the hydrogenation reaction at thistemperature is suificient for the achievement of the rise intemperature. It is also possible, however, to supply to the reactionmaterial additional heat, for example by intermediate heating up or bythe addition of hot gases at one or more places or by the addition ofgases, as for example carbon monoxide or oxygen, which under thereaction conditions react with the hydrogen with the production of heat.

In general the same pressure is chosen for the pretreatment as is usedin the subsequent pressure hydrogenation. As hydrogenating gas there maybe used pure hydrogen or gases containing hydrogen, such as illuminatinggas, town gas, watergas, cracking gas, coke-oven gas or low temperaturecarbonization gas. As large-surfaced substances there are suitableporous substances or non-porous substances, especially open hollowbodies, as for example rings, hemispheres or angular structures, such ascubes, cones, truncated cones, boxes or pyramids which are open on atleast one side and which if desired contain in the hollow spacedeflecting plates; for example there may be mentioned metallicmaterials, for example metals of the 8th group or alloy steels, orceramic materials, such as porcelain, clay, cement, pumice, bleachingearths, aluminas or synthetically prepared silicates, graphite andplastics. In many cases it has proved to be preferable to add to theselargesurfaced substances a small amount of a catalyticallyactingsubstance, such as molybdenum, tungsten, chromium, vanadium, nickel,cobalt, platinum, ruthenium, gold, manganese, titanium or compounds ofthese or mixtures of the said elements or their compounds.

The reaction chamber is arranged with large-surfaced substances, so thatthe free space is about 40 to especially 50 to 70%, the free space inthe reaction chamber being regarded as the intermediate spaces andbetween the large-surfaced substances and the hollow spaces within thelarge-surfaced substances. This is achieved, for example, as alreadydescribed, by using the said substances in the form of suitable rings orother surface-forming voluminous open or partly closed structures.

The chamber for the large-surfaced materials is in general smaller thanthe reaction vessel proper which is provided with the hydrogenationcatalyst and in which occurs the refining, destruction or/ andaromatizing pressure hydrogenation, advantageously in a plurality ofstages, at pressures of 5 to 700 atmospheres, especially 20 to 300atmospheres, and at temperatures of 350 to 550 C., preferably at risingtemperature. The amounts of hydrogen to be used amount to 100, 200, 300,500, 1,000'or 3,000 litres per kilogram of initial material and it isadvantageous to choose a throughput of 0.3 to 10 kg. of initial materialfor each part by volume of catalyst per hour. In general the throughputthrough the vessel containing the large-surfaced material is larger thanthe throughput through the reaction vessel provided with thehydrogenation catalyst. Mostly it is larger, at least about 1 kg.

The circulating gas containing hydrogen can be washed with an extraneousoil or an oil originating from the process, for example with a heavygasoline or a gas oil. To remove ammonia, the gas may be treated withwater or an acid solution, if desired in conjunction with an oilwashing. To remove H S the circulating gas or part of it can be washedwith solvents known in the art. The

washing may take place in cocurrent or countercurrent, preferably underthe reaction pressure.

As catalysts for the treatment there come into question those which havehydrogenating, rafiinating, cracking, dehydrogena-tin'g, isomerizingand/ or cyclizing properties, for example oxides, sulfides, selenides,tellurides, sulfates, borates, nitrates, carbonates, halides,phosphorous compounds or also silicates of vanadium, molybdenum,tungsten, chromium, uranium, rhenium, iron, nickel or cobalt, as well asgold, silver, copper, tin, titanium, lead, zinc, magnesium, cadmium,Zirconium, antimony, bismuth and manganese as well as the metals of theplatinum, palladium and iron groups and the heavy metals of the 1stgroup or mixtures of the same. Thus there may be used for example thesaid compounds of molybdenum, tungsten, chromium or vanadium inadmixture or in chemical combination, for example as molybdates,tungstates, chromates, chromites, vanadates or titanates, with compoundsof nickel, cobalt, titanium, tin or lead or/ and with the metals of theplatinum and palladium groups or/and heavy metals of the 1st group aswell as their compounds, the added substances preferably being used insmaller amounts than molybdenum, tungsten, chromium or vanadium. Forexample molybdenum or tungsten with cobalt, nickel and/or titanium andif desired tugnsten or molybdenum are especially suitable. Some elementshave proved to be promoters for the more usual catalysts of the 5th to8th groups of the periodic system, for example gold, silver, mercury,titanium, copper, zinc, tin or uranium and lead or their compounds.Mixtures consisting of the compounds of the said metals of the 4th groupof the periodic system, for example of titanium, with the compounds ofiron, nickel, cobalt or manganese, as well as of copper, silver, gold,platinum, palladium, ruthenium or their compounds .or in chemicalcombination as titanates, are also suitable. The compounds of the metalsof the iron group in admixture with platinum, palladium, ruthenium,copper, silver, gold or their compounds also come into question. Thesemixtures may also be used in the form of chemical compounds. Theactivity of the catalysts can be adjusted with compounds of the alkaliand alkaline earth metals because these influence the activity. The saidcatalysts may be applied in a moist or calcined state to carriers in anamount of 0.1 to 30% by weight. As carriers there may be usedacid-treated montmorillonite, active silicic acid, silica gel,preferably together with the oxides of titanium, thorium, zirconium andmagnesium, titania gel or titanium oxide, if desired together with 0.1to 30% by weight of SiO as silicates, bleaching earths, fullers earth,synthetic silicates, for example aluminum and/or magnesium silicates, aswell as the abovementioned silicates, active aluminas, preferably with asurface of more than 300 square meters per gram, aluminum hydroxide orpeptized aluminas which are treated with an amount of acid insuflicientfor complete solution, bauxite, if desired with 1.1 to 25% by weight ofSiO;,,, titanium oxide, zirconium oxide, cerium oxide, zinc oxide and/or magnesium oxide. When using synthetically pre pared carriers, such assilicic acid, silicates, aluminas or titanium oxide, the catalyticallyactive components may be added already during the preparation by addingfor example a soluble compound of the catalytically active 'metal to aWaterglass solution, silica sol, titanium salt solution, aluminum saltsolution or/ and aluminate solution and then precipitating the solutionand/ or by adding the metal or the metal compound during theprecipitation. It is advantageous, also to treat the carrier with gases,such as ammonia, hydrogen, sulfur dioxide, halogen or rare gases,..andthe gas may remain in the pores. The carrier may also be pretreated withhydrogen halide or an inorganic or low-molecular weight organic monobasic or dibasic acid, among which may be mentioned for; examplelhydrochloric acid,hydrogen fluoride, chlorsulfonic acid, formic acid oroxalic acid. The carrier crease in the pressure difference takes place.

may absorb halogen in an amount of 0. 1 to 10% by weight. The catalystmay also be shaped with carbon and the carbon then wholly orsubstantially removed by burning off.

When working under pressures up to about 150 atmospheres, the catalystis generally regenerated from time to time with oxygen or anoxygen-containing gas at temperatures of 450 to 600 C. The catalyst orthe catalyst carrier may also be exposed for a long time to atemperature above 300 C., for example 400 to 600 0., prior to its use.

The catalysts may be rigidly arranged in known manner in the reactionchamber or they may be present in the reaction chamber in a movingcondition. The initial material may be led with hydrogen in cocurrent orcountercurrent over the catalyst;

The following examples will further illustrate this invention but theinvention is not restricted to these examples.

Example 1 The constituents boiling up to 365 C. are separated bydistillation from a Near East crude oil. The residue boiling above 365C. is heated up to 330 C. under a pressure of 100 atmospheres togetherwith hydrogen and led into a preliminary vessel I which is filled withRaschig rings of aluminawhich have been impregnated with 4% by weight ofM00 of the interior of the vessel is free space. The throughput, withreference to this first vessel, amounts to 1:8 kilograms of residue perlitre of Raschig rings per hour. The temperature at the exit from thefirst vessel amounts to 360 C. The gas and oil mixture is heated up to408 C. and led into a preliminary vessel II which is filled with Raschigrings of the same composition. The throughput, with reference to thesecond preliminary vessel, amounts to 1.0 kilograms of residue per litreof Raschig rings per hour. The temperature at the outlet of the secondpreliminary vessel is 435 C. The gas and oil mixture then passes at thistemperature into a third vessel (the reaction chamber proper) which isfilled with a rigidly arranged catalyst. The catalyst consists of activealumina with 5% of silicic acid which has been provided with cobalt andmolybdenum oxide in such a way that the finished catalyst contains 3% byweight of Co and 10% by weightyof molybdenum (calculated as metal). Thethroughput, with reference to this reaction chamber, amounts to 0.5kilogram per. litre of catalyst per hour. The ratio of hydrogen to oilamounts to 0.8 cubic metre of gas per kilogram of oil. The reactiontemperature is 430 C. p

A stripping product is obtained with 70% by weight of components boilingup to 480 C. anda sulfur content of 116% by weight, whereas thedistillation residue introduced contained only 34% by weight ofcomponents boiling up to 480 C; and 4% by weight of sulfur.

After an operational period of two months, an in- The system is thenshut off and the catalyst present in the hydrogenation vesselregenerated with nitrogen and air.

Treatment of the alumina Raschig rings in the preliminary vessels I andII is not necessary. These vessels are reconnected, after the end of theregeneration of the catalyst, with the reaction chamber properand usedagain for the refining treatment of distillation residue 'as abovedescribed. In order to avoid shutting off the system, it is alsopossible to switch in a second reaction chamber containing freshcatalyst.

The solid ash contained in the residue and also the ash constituentsnewly formed by decomposition of the organo-metallic compounds separatein the preliminary vessels. After an operational periodof four months,the vessels I and II are emptied. The Raschig rings are separated fromthe ash constituents and returned to the vessels.

Example 2 A German crude oil from Emslaud is heated up to 320 C. under apressure of 240 atmospheres together with 2 cubic metres of gascontaining hydrogen per kilogram of crude oil, and led into apreliminary vessel which is filled with Raschig rings of magnesia cementwhich have been impregnated with 5% by weight of M A free space of 70%by volume is present in this vessel filled with Raschig rings. Thethroughput with reference to this preliminary vessel amounts to 1.9kilograms of oil per litre of Raschig rings per hour. The temperature isallowed to rise in this preliminary vessel so that at the outlet atemperature of 425 C. prevails. A small part of gas containing hydrogenis heated up to 400 C. and introduced into the second part of the vesselthat an exit temperature of 425 C. is reached. From the lower part ofthe preliminary vessel 0.8% by weight of oil with reference to theamount of crude oil introduced is continuously withdrawn.

The oil vapors are heated together with the gas up to 430 C. and thenpass into the reaction chamber proper which is filled with rigidlyarranged catalyst. The catalyst consists of a synthetic aluminumsilicate which contains 5% by weight of molybdic acid. The throughput inthe hydrogenation chamber amounts to 0.6 kilogram of oil per litre ofcatalyst per hour.

Behind the reaction chamber there is withdrawn a stripping product with77% by weight of constituents boiling up to 480 C., whereas the initialoil contained only 31% by weight of these constituents.

After an operational period of 2,250 hours the system is shut off andopened. The ash contained in the crude oil and the ash newly formed bydecomposition of the organo-metallic compounds has collected in thepreliminary vessel in and between the Raschig rings and can readily beseparated from the Raschig rings. There is practically no coke formationin the reaction chamber proper or in the preliminary vessel.

I claim:

1. In a process for the pressure hydrogenation of an initial materialselected from the class consisting of crude oils, shale oils, tars andtheir residues at temperatures between 350 C. and 550 C. wherein saidinitial material is preheated in a preliminary stage while beingcontacted with large-surfaced substances for removal of ash and thenintroduced into a succeeding stage for said pressure hydrogenation, theimprovement which comprises heating said initial material while passingit through said preliminary stage from an initial temperature above 250C. but below 400 C. to a temperature of at least 30 C. higher than saidinitial temperature, said preliminary stage being formed by at least onereaction chamber containing said large-surfaced substances and having afree space of at least 40% up to about 2. The improved process of claim1 wherein said largesurfaced substances provide a free space in saidpreliminary stage of at least 50% 3. The improved process of claim 2wherein the initial temperature in said preliminary stage is at least300 C.

4. The improved process of claim 2 wherein the preliminary stage iscarried out in more than one reaction chamber, and the temperature ofthe initial material being treated rises in at least one of saidchambers.

.5. The improved process of claim 4 wherein intermediate heating isapplied between the reaction chambers.

6. In a process for the pressure hydrogenation of an initial materialselected from the class consisting of crude oils, shale oils, tars andtheir residues at temperatures between 350 C. and 550 C. wherein saidinitial material is preheated in a preliminary stage while beingcontacted with large-surfaced substances for removal of ash and thenintroduced into a succeeding stage for said pressure hydrogenation, theimprovement which comprises heating said initial material while passingit through said preliminary stage from an initial temperature above 300C. but below about 350 C. to a temperature of at least about 50 C.higher than said initial temperature, said preliminary stage beingformed by at least one reaction chamber containing said large-surfacedsubstances providing a free space of about 50% to about 80%, andwithdrawing from said preliminary stage about 0.1 to 2% by weight, withreference to the initial material, of an ash-containing high-boilingoil.

7. The improved process of claim 6 wherein the throughput in thesucceeding pressure hydrogenation stage is about 0.3 to 10 kilograms ofinitial material for each part by volume of catalyst per hour, and thethroughput of initial material in the preliminary stage is larger thanthe throughput of the succeeding pressure hydrogenation stage.

References Cited in the file of this patent UNITED STATES PATENTS1,932,174 Guas et a1 Oct. 24, 1933 1,974,057 Steffen et a1. Sept. 18,19.34 2,848,376 Oettinger et a1 Aug. 19, 1958 I 1 UNITED STATES PATENTOFFICE CERTIFICATE OF CORRECTION Patent No. 2,985,5532' May 23 1961Willi Oettinger It is hereby certified that error appears in the abovenumbered patent requiring correction and that the said Letters Patentshould read as corrected below.

Column 2, line 41, strike out- "and"; column 4, line 37, for "1.0kilograms" read 1,9 kilograms Si ned and sealed this 5th day of December19610 (SEAL) Attest:

ERNEST W. SWIDER Attesting Officer DAVID L. LADD Commissioner of PatentsUSCOMM-DC

1. IN A PROCESS FOR THE PRESSURE HYDROGENATION OF AN INITIAL MATERIALSELECTED FORM THE CLASS CONSISTING OF CRUDE OILS, SHALE OILS, TARS ANDTHEIR RESIDUES AT TEMPERATURES BETWEEN 350*C. AND 550*C. WHEREIN SAIDINITIAL MATERIAL IS PREHEATED IN A PRELIMINARY STAGE WHILE BEINGCONTACTED WITH LARGE-SURFACED SUBSTANCES FOR REMOVAL OF ASH AND THENINTRODUCED INTO A SUCCEEDING STAGE FOR SAID PRESSURE HYDROGENATION, THEIMPROVEMENT WHICH COMPRISES HEATING SAID INITIAL MATERIAL WHILE PASSINGIT THROUGH SAID PRELIMINARY STAGE FROM AN INITIAL TEMPERATURE ABOVE250*C. BUT BELOW 400*C. TO A TEMPERATURE OF AT LEAST 30*C. HIGHER THANSAID INITIAL TEMPERATURE, SAID PRELIMINARY STAGE BEING FORMED BY ATLEAST ONE REACTION CHAMBER CONTAINING SAID LARGE-SURFACED SUBSTANCES ANDHAVING A FREE SPACE OF AT LEAST 40% UP TO ABOUT 80%.